CONFIG_LEGACY_BOARD_OCELOT is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Legacy support for Ocelot based boards

modulename: board-ocelot.ko

configname: CONFIG_LEGACY_BOARD_OCELOT

Linux Kernel Configuration
└─>Legacy support for Ocelot based boards
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
/arch/mips/generic/board-ocelot.c